This is my experience with 90's Jetta 1.8 digifant having problems with cold start and hesitation
Problem Description: When you turn the ignition the engine starts for a few seconds , after that the engine stall and die
The engine start but you can only keep it running at hight RPM, after warm up it runs fine
The engine starts, run fine for a while then die
Iddle problems
Does this problem sound familiar to you? Jetta are not a good cars, 1992 its the worst was assembly in Mexico, can you imagine those little mexicans eating and drinking jalapeņos with tequila. Well, this its only for people who knows a little about mechanic, if you have the money or dont have a clue, dont try.
1. Check tank fuel pump, you can do it in or out, remove the incoming fuel hose right next to the fuel presure regulator, drink a 20oz beer and put the end of the hose in there, crank the car couple times and you should have 50psi or 1/4 can full, if not, fuel pump located inside fuel tank in the trunk its busted.Outside, get the pump out and give 12 volts from the battery, watch sparks and fuel tank or you may not need your Jetta
2.Fuel presure regulator, dont know how to check it and its very unusual to be bad
3. Clean the iddle screw (co) on the front of the intake manifold pull it out and carburator cleaner with it, as well to the PCV valve and O2 sensor
4. If the problem still, then disconect the two water sensors on the upper radiator hose housing, one blue and the other black, if the problems goes away then you know what to do, drink another 20 oz can of beer and go to the yunk yard, that sensor shorts and draw the voltage from the computer, The one mos important its the blue. At 85 F suppose to have 1500-2100 ohms.
Other problems like ignition switch, fuel filter, Computer $$$ , broken grounds, catalytic converter,air flow sensor and vacuum leaks, EGR
Now good luck and let me know if it works out for you
how did you know
